1. Field of the Invention
The present invention relates to an apparatus for purifying and activating water by effectively retaining air in water for a long period of time.
2. Description of the Prior Art
For purifying water in nurseries or farms for growing fishes and shellfishes and in water-culturing plants, an apparatus is known which supplies air to pipings immersed in water by means of a compressor or blower so as to eject the air as bubbles into water through a plurality of small apertures provided at one end of the piping. An apparatus is also known which includes a waterwheel located at a position adjacent to the surface of water and driven for example by a motor to generate water splashes, so as to supply water with a large amount of bubbles. Recently, a submerged pump of a self-suction type and jet pump are also known.
Such conventional apparatus, however, can merely provide water with bubbles having a relatively large particle size. Thus, bubbles generated by such apparatus have a relatively large buoyancy and for this reason they easily go up to the surface of water in a short time. Retention time of such bubbles in water is therefore insufficient to purify water concerned.
A nursery or farm for eels in particular requires high purification performance since, in such a place, it is not desirable to supply water frequently. The above apparatus do not meet such a requirement. That is to say, such apparatus could not sufficiently purify water in a nursery for eels even when they had been operated continuously, so that various inconveniences have resulted from toxic substances generated from remaining bait or body waste discharged from eels.